Robert Kubica's difficulty in adapting to Pirelli's new tyres is allegedly the reason behind Williams decision to run Sergey Sirotkin alongside Lance Stroll this year.
Polish sports website Sportowefakty.wp.pl published an interview with BBC's Andrew Benson in which the F1 reporter offered some insight on what transpired during the post-race Pirelli tyre test in Abu Dhabi at the end of November.
While details about the relative performance of Kubica and Sirotkin were scarce, the Russian driver apparently delivered a superior result, and proved faster on Pirelli's new rubber.
"The main issue for Robert was primarily the speed on “qualifying” laps, during which the car has a small amount of fuel in the tank," Benson is quoted by Sportowefakty.wp.pl.
"Kubica, on all his runs using the tyres could not significantly improve performance.
"I also received information that the 33-year-old himself revealed to his manager his problems with adapting to the new tyres provided by Pirelli.
"There is nothing strange about this. Many regular F1 drivers complain about the revolutionary tires of the Italian company.
"For Kubica, however, the adaptation process can be a much more difficult challenge. Unlike the rest of the drivers, the Pole has not driven any of the last six seasons since Pirelli became F1’s partner.
"In the end, Williams management in Grove decided that Kubica couldn’t get the job done and that in their current situation there is no room for risk. Hence the choice of Sirotkin."
If Williams' view is that running Kubica would pose too much of a risk, one wonders how they evaluate the risk of running one complete rookie - Sirotkin - alongside 19-year-old Lance Stroll whose experience is building but still remains limited.
Benson reported last week that Williams was currently in the process of finalising Sirotkin's contract, with an announcement due any day.
The 22-year-old Russian driver's cause was also likely helped by his financial support package, courtesy of his long-time backers SMP and worth a reputed $20M.